The Jingweon Mafia originated in South Korea but, during the 1970's it established a foothold in Tokyo's underworld, where it eventually became enemies with that city's reigning local crime syndicate, the Tojo Clan.
The mafia itself consists of well-trained operatives, trained in hand-to-hand combat and weapon usage. Their primary form of attire consists of dark clothing, frequently with combat boots and military camo.
It's famous for their "death before dishonor" creed, in which the mafia's operatives are obliged to commit suicide rather than living in dishonor for failing to carry their missions. To do this, Jingweon operatives usually wear a ring which contains a poisonous powder hidden inside its jewel crown. Additionally, the murder of any member of the Jingweon must be paid back with the murder of their killer, lest the entire organization be shamed.
During the late 1970's, the Jingweon and the Tojo had gotten into a years-long war for control over the Tokyo underworld and, by 1980, the Tojo Clan was losing. However, Dojima Family patriarch Sohei Dojima got information suggesting that the Jingweon's leadership would be attending a party in the warehouse behind one of their clubs in christmas of 1980. Seizing on the opportunity, Dojima sent a platoon of assassins led by his two lieutenants, Shintaro Kazama and Futoshi Shimano, to take out the Jingweon's leaders.
Kazama, reluctant to commit such a massacre, tried to warn the Jingweon leader so he would flee town before the massacre could commence. However, Kazuma Kiryu, Kazama's protege who had followed him to the warehouse party, mistakenly believed that the Jingweon Boss was trying to kill Kazama and intervened, attacking him. Kazama proceeded to kill the Jingweon leader to protect Kiryu and, hearing his gunshots, Shimano and the rest of the Dojima assassins sprang into action and began massacring the rest of the Jingweon leaders present.
36 members of the Jingweon were killed in what came to be known as the "Kamurocho Christmas Massacre", including the entirety of the Jingweon's leaders and many of their bodyguards. Of those present at the massacre, only five Jingweon survived: three young bodyguards whom Kazama took pity on and helped escape, called Daejin Kim, Yeongmin Ji and Hoejong Park; and the boss' wife, Suyeon Jung, and her young child, who were helped by the first police officer on the scene, Jiro Kawara.
After the massacre, the Jingweon were thought to be wiped out in Japan. However, Kim and Ji went into hiding, promising to one day get into contact with the Jingweon's mainland organization to plot their revenge against the Tojo Clan. Said plan came to be 26 years after the Christmas Massacre, in 2006.
By that year, Kim (living under the alias of "Yukio Terada") had infiltrated the Tojo Clan and risen to become it's fifth chairman, while Ji (under the name "Wataru Kurahashi") had become the Tokyo Metropolitan Police's superintendent for the Foreign Affairs Division. Kim faked his own murder by Omi Alliance assassins in order to spark a war between the Tojo and the Omi, in the hopes that it would finally destroy the very weakened Tojo Clan. In order to aid that destruction, the Jingweon also prepared a multitude of bombs that they intended to place all over Tojo Clan businesses in Tokyo and detonate them when the Omi Alliance made their move against them.
Unfortunately for the Jingweon, Kiryu and his allies, Kaoru Sayama, Makoto Date and Jiro Kawara discovered the Jingweon's return and began to uncover their schemes. Ji was eventually discovered as an infiltrator and killed by Sayama during a confrontation in Millenium Tower. Additionally, the bombs were also discovered and defused by Goro Majima and his construction company before they could be detonated.
When the Omi Alliance invasion failed to eradicate the Tojo, Kim took direct action and decided to murder Kiryu, Sayama and the Tojo's leadership personally. He revealed his ruse to Kiryu by showing up after his fight with Ryuji Goda atop the Kamurocho Hills construction site and, along with a platoon of Jingweon assassins, tried to kill him. Regardless, Kiryu and Sayama managed to defeat him and his forces. Kim would soon after be killed by Ryo Takashima, the chief of Omi headquarters, who had been acting as his informant but who decided to betray him in order to take power for himself.
The mafia returned for a second time in 2016, now led by Joon-gi Han, who holds a personal grudge against Kiryu for what happened in 1980.
- Jingweon Mafia Boss - Original leader of the Japanese branch (Deceased)
- Suyeon Jung - Wife of the original Jingweon Boss (Deceased)
- Daejin Kim - Also known as Yukio Terada. Former bodyguard to the original boss and later 5th Chairman of Tojo Clan. (Deceased)
- Yeongmin Ji - Also known as Wataru Kurahashi. Former bodyguard to the original boss and later superintendent for the Tokyo Metropolitan Police's Foreign Affairs division. (Deceased)
- Hoejong Park - Also known as Murai. One of the survivors of the Christmas Massacre, who would go on to abandon the Jingweon and their creed.
- Tsumura - Hacker and bomb maker who would participate actively in Daejin Kim's plot to destroy the Tojo Clan in 2006. (Deceased)
- Jinwu Kang - Member who would undergo plastic surgery to resemble Kazuki in order to move about Kamurocho to aid Daejin Kim's revenge plan without arousing suspicion. (Deceased)
- Man in Black - Assassin who would try to kill Kazuma Kiryu multiple times in 2006. (Status Unknown)
- Joon-gi Han - New leader of the Jingweon's Japanese branch in 2016 who sought to reform the Jingweon into being more like a Japanese-style yakuza family. (Deceased)
- Kim Yong-Soo - Member who underwent plastic surgery to serve as a decoy Joon-gi Han. Eventually defected to join the Geomijul.
- Seong-Hui - Former member of Jingweon Mafia. currently the leader of the Geomijul.